// Multiple file selector by Stickman -- http://www.the-stickman.com 
// with thanks to: [for Safari fixes] Luis Torrefranca -- http://www.law.pitt.edu and Shawn Parker & John Pennypacker -- http://www.fuzzycoconut.com [for duplicate name bug] 'neal'

var validExtensions = new Array(".gif",".jpg",".png",".txt",".pdf",".doc",".zip",".rar",".tar",".gz",".txt",".xml" );

function checkFileType( file) {
	var allowSubmit = false;
	var type = file.slice(file.indexOf("\\") + 1);
    var ext = file.slice(file.lastIndexOf(".")).toLowerCase();
    //loop through our array of extensions
    for (var i = 0; i < validExtensions.length; i++) {
        //check to see if it's the proper extension
        if (validExtensions[i] == ext) {
            allowSubmit = true;
        }
    }
	return allowSubmit;
}
function MultiSelector( list_target, max ){
	this.list_target = list_target;
	this.count = 0;this.id = 0;

	if( max ){this.max = max;} else {this.max = -1;};
	this.addElement = function( element ){
		if( element.tagName == 'INPUT' && element.type == 'file' ){
			
			// get element list free
			if( max ) {
				for(i = 0; i < max; i++) {
					if(document.getElementsByName('file_'+i).length == 0) {
						element.name = 'file_' + i;
						break;
					}
				}
			} else {
				element.name = 'file_' + this.id++;
			}
			if(!element.name) {
				element.name = 'file_0';
			}
			element.multi_selector = this;
			element.onchange = function(){
				if( !checkFileType( element.value)) {
					alert("Only files with extensions " + ( validExtensions.join("  ").toUpperCase()) + " are allowed");
					element.value = "";	
					return false;			
				} else {
					var new_element = document.createElement( 'input' );
					new_element.type = 'file';
					this.parentNode.insertBefore( new_element, this );
					this.multi_selector.addElement( new_element );
					this.multi_selector.addListRow( this );
					this.style.position = 'absolute';this.style.left = '-1000px';	
				}
		};
		if( this.max != -1 && this.count >= this.max ){
			element.disabled = true;};
			this.count++;
			this.current_element = element;
		} else {
			alert( 'Error: not a file input element' );
		};}
	;
	
	this.addListRow = function( element ){
		
		var new_row = document.createElement( 'div' );
		var new_row_button = document.createElement( 'input' );
		new_row_button.type = 'button';
		new_row_button.setAttribute('style','width:50px');
		new_row_button.value = 'Delete';
		new_row.element = element;
		new_row_button.onclick= function(){
			this.parentNode.element.parentNode.removeChild( this.parentNode.element );
			this.parentNode.parentNode.removeChild( this.parentNode );
			this.parentNode.element.multi_selector.count--;
			this.parentNode.element.multi_selector.current_element.disabled = false;
			return false;
		};
		new_row.innerHTML = element.value;
		new_row.appendChild( new_row_button );
		this.list_target.appendChild( new_row );
	};
	
	
};